Clay Blocks Research Articles

Reusing the Coconut Clay (Brick) as Construction Material

With the aim of finding an alternative for the manufacture of concrete, based on the recycling of construction debris and demolition of works, in particular the reuse of the clay blocks (brick), a mechanism that will serve to improve the visual appearance within The city and to diminish accumulation of these in vacant lots and even in the municipal dumps the investigation was developed, through the method of observation and experimentation in laboratory, field, and documentary...

酸化マンガン（IV）を固定化した陶土の調製とそれを利用した実践研究―過酸化水素水中の上下運動の観察―

酸化マンガン（IV）を固定化した陶土の調製とそれを利用した実践研究―過酸化水素水中の上下運動の観察―

Seismic Response of URM Walls Strengthened with FRP Reinforced Coating

A set of individual URM walls as well as an assemblage of a three-storey URM hollow clay block masonry structure composed of two shear- and two cross-walls have been tested in original and strengthened state. As a method of strengthening, the coating of the walls, consisting of glass fiber reinforced polymer (GFRP) grid laid in fiber reinforced cementitious mortar matrix (sometimes called textile reinforced mortar), anchored to the walls with glass fiber anchors, has been used. All specimens were subjected to constant vertical load simulating the effect of gravity loads and cyclic horizontal displacements with step-wise increased amplitudes, induced either at the top of the walls or at the floor levels of the assemblage, simulating the effect of seismic loads.The observed behaviour and failure mechanisms were of the shear type. The results show that by the application of FRP reinforced coatings, the seismic performance of URM structures can be significantly improved. As the results of experiments indicate, the energy dissipation, displacement capacity and shear resistance of URM increase substantially. In this regard, adequate anchoring of coating to the masonry and into the r.c. floor structures is essential.

The compressive strength of vertically perforated clay block masonry predicted by means of a unit-cell type numerical simulation tool taking discrete cracking into account

Vertically perforated clay blocks with an excellent ratio of load-bearing capacity to thermal properties are highly sophisticated products, which due to their higher complexity require advanced design concepts for a reliable prediction of performance characteristics. Since the contact between blocks strongly influences the compressive strength, it is insufficient to consider single block strengths. To tackle this challenge, our numerical simulation tool is based on a unit-cell approach with periodic boundary conditions, so interaction between blocks can be considered. An extended finite element approach allows for modelling discrete cracks and, thus, brittle failure modes and compressive strengths can be predicted correctly.

Development and hygric and thermal characterization of hemp-clay composite

This study investigates the use of clay as binder in hemp composite and compares hemp–clay composite to hemp–lime concrete. The clay is produced from washing mud from gravels production site. Two clay drying temperature are used. The thermal properties are measured with a hot wire method and the hygric characterization is based on the measurement of Moisture Buffer Value. Performances obtained on clay blocks, hemp–clay composite and hemp–lime composite are compared. The results show that the two clay drying temperatures do not impact on the thermal conductivity nor on the moisture buffer value of clay blocks. Hygric and thermal performances of hemp–clay and hemp–lime composites with the same density are close. These materials act as excellent hygric regulators. Performances measured separately on hemp and clay underline an interesting synergetic effect in the case of hemp–clay composite leading to a higher ability to the moisture buffering. Such material can be advantageously used in buildings to moderate indoor humidity variations.

Masonry walls with a multi-layer bed joint subjected to in-plane cyclic loading: An experimental investigation

A series of static-cyclic shear tests on full-scale unreinforced masonry (URM) walls with multi-layer bed joints have been performed within a research project on the seismic behaviour of unreinforced masonry walls with soft layer membrane placed in the bed joint to induce sliding. Walls were made using typical perforated Swiss clay blocks and standard cement mortar and the so-called multi-layer bottom bed joints, which comprise a core soft layer protected by two layers of extruded elastomer and placed in the middle of mortar joint. The preliminary testing phase was aimed at choosing the most suitable core soft layer type among the four types considered (rubber granulate, cork, cork-rubber granulate and bitumen). The main testing phase comprised five tests on storey-high URM specimens with rubber granulate core soft layers performed to investigate the influence of the size, the pre‐compression level and the aspect ratio on the seismic behaviour of URM walls with a multi‐layer bed joint. Sliding occurred in all tested specimens. However, the final failure mode as well as the displacement capacity of test specimens were governed by the extent of shear and tensile (vertical) cracks that developed from the bottom brick course. The response of specimens can be interpreted using a multilinear horizontal force-displacement response idealization, whose parameters can be estimated using the proposed equations.

Comparison of environmental benchmarks of masonry and concrete structure based on a building model

Construction materials have distinguished energy consumptions and different emissions of carbon dioxide from fabrication up to application. The processes and the treatments needed to transform the raw materials into the final products, the transport to the construction sites and the techniques used for their application, all contribute to the differences in embodied energy and carbon footprint of these materials. In an environmental assessment one wonders what kind of constructive solution is environmentally more favorable. This study refers to the environmental comparison of reinforced concrete and clay bricks. Through a digital three-dimensional building model the required data are analyzed. The building is once considered with a reinforced concrete structure, consisting of columns, beams and slabs, with brick walls in between the columns in the periphery and interior of the building. Then, structural masonry with clay blocks in the exterior and interior walls is studied. Both models are analyzed in two versions. In the first version the slabs are of reinforced concrete and in the second version the slabs are built in pre stressed concrete beams and clay blocks. The building model represents for all solutions equal conditions. The comparison is limited to the quantification of the most important environmental parameters, the embodied energy and CO2 emissions. The results of this study show that the Masonry Model Version 1 has a 11% reduction in CO2 and 12% reduction in energy consumption, while Version 2 of both models has a 39% reduction in CO2 emissions and 41% reduction in embodied energy in case of Masonry Model and 30% reduction in CO2 emissions and 32% embodied energy in case of the Concrete Model compared to the Concrete Model with reinforced concrete slabs. These differences are due to the reduction of reinforced concrete, which is more significant in Versions 2.

An Evaluation of Marine Sediments in Terms of their usability in the Brick Industry: Case Study Port of Koper

A dredging process is essential for the development of harbours and ports, allowing the functional daily operation of the port. The management of dredged material represents a worldwide challenge, especially considering unwanted deposition of material. Because of their chemical, petrographic, mineralogical and homogeneity composition, marine sediments could represent an appropriate raw material for the brick industry, particularly for the production of clay blocks, roofing and ceramic tiles. In this study dredged material from Port of Koper was tested for such use, thus various analyses were carried out in order to determine if the dredged material is environmentally friendly and suitable for use in the brick industry. These included: chemical analysis, mineralogical analysis, particle size analysis, chloride content analysis and tests of firing in a gradient furnace. Furthermore, tests of mechanical properties, as well as tests of the frost-resistance of the samples were carried out. On the basis of the primary analyses and samples prepared in a laboratory, it was confirmed that marine sediments from the Port of Koper, without any additives are only conditionally suitable as a source material for producing brick products, because without additives they exhibit too much shrinkage on drying and firing, as well as high water absorption, this can be improved by the incorporation of suitable additives, for example, virgin clay or other suitable waste material. The approach described herewith can also be followed to assess sediments from other ports and rivers regarding its potential use in clay brick sector.

Properties of Mortar with Red Gypsum as Cement Replacement Material by Using Industrial Approach Method

Utilization of Red Gypsum, a common industrial waste, in the manufacturing of cement brick can mitigate the deterioration of environment as it can preserveland piling of RG waste. X-Ray fluorescence analyzer was utilized to determine the chemical composition of Red Gypsum (RG) while sieving method was used to determine its particle size distribution. From the analyses, it can be concluded that RG properties suit the purpose of replacing cement for production of low strength mortar. A range of physical and mechanical tests were conducted on various percentage of cement replacement in RG cement bricks. This paper focused on verifying formulation and water ratio to meet the compressive strength tests needed as required for low strength mortar and the effects on the quality. From the results of this study, it can be concluded that RG cement bricks complied with the Malaysian Standard 76:1972 (Specifications for bricks and blocks of brick earth, clay or shale) for non-load bearing walls. The results also indicated that a maximum range of 60-70% replacement can be done without compromising the minimum quality of the produced bricks.

Study on heat transfer characteristics of straw block wall in solar greenhouse

A new type of solar greenhouse with straw block north wall was developed. The heat transfer characteristics, temperature, heat absorption, release and loss of its north wall were investigated by theoretical and experimental analyses and the economic and environmental evaluations of north walls were carried out. The thermal storage coefficient of heat storage layer, the total thermal inertia index and the total thermal resistance of the new type straw block north wall (ST) were 38.5%, 13.9% and 25.4% higher than that of porous clay block north wall (CL), respectively and the average air temperature of Chinese solar greenhouse with ST was 0.7°C higher than that of Chinese solar greenhouse with CL on cloudy day. The temperature of heat storage layer as well as the heat absorption and release of ST were higher than that of CL. The heat loss of ST was less than that of CL. Compared to CL, the cost, energy consumption and CO2 emissions of ST were reduced 26.3%, 81.7% and 29.4%, respectively. ST had better thermal properties and could improve thermal environment of greenhouse. Besides, it was low-cost and environmentally friendly.

Effect of Compaction on Compressive Strength of Unfired Clay Blocks

Effect of Compaction on Compressive Strength of Unfired Clay Blocks

Reactive transport modelling of groundwater-bentonite interaction: Effects on exchangeable cations in an alternative buffer material in-situ test

Bentonite clays are regarded a promising material for engineered barrier systems for the encapsulation of hazardous wastes because of their low hydraulic permeability, swelling potential, ability to self-seal cracks in contact with water and their high sorption potential. SKB (Svensk Kärnbränslehantering) has been conducting long term field scale experiments on potential buffer materials at the Äspö Hard Rock Laboratory for radioactive waste disposal in Sweden.The Alternative Buffer Material (ABM) test examined buffer properties of eleven different clay materials under the influence of groundwater and at temperatures reaching up to 135 °C, replicating the heat pulse after waste emplacement. Clay materials were emplaced into holes drilled in fractured granite as compacted rings around a central heater element and subsequently brought into contact with groundwater for 880 days. After test termination, and against expectations, all clay materials were found to have undergone large scale alterations in the cation exchange population. A reactive-diffusive transport model was developed to aid the interpretation of the observed large-scale porewater chemistry changes. It was found, that the interaction between Äspö groundwater and the clay blocks, together with the geochemical nature of the clays (Na vs Ca-dominated clays) exerted the strongest control on the porewater chemistry. A pronounced exchange of Na by Ca was observed and simulated, driven by large Ca concentrations in the contacting groundwater. The model was able to link the porewater alterations to the fracture network in the deposition hole. The speed of alterations was in turn linked to high diffusion coefficients under the applied temperatures, which facilitated the propagation of hydrochemical changes into the clays. With diffusion coefficients increased by up to one order of magnitude at the maximum temperatures, the study was able to demonstrate the importance of considering temperature-dependant diffusion in understanding and predicting geochemical alterations of engineered barriers systems after relatively short exposure times following waste emplacement.

Multi-Performance Innovative Infill Panels

Infill panels and partitions are widely used non-structural elements in reinforced concrete buildings, characterized by a significant seismic vulnerability as testified by disastrous collapses observed during recent earthquakes, for both in-plane and out-of-plane actions. The most advanced building codes foresee mandatory verifications of these elements, both when designing a new building and when assessing the seismic adequacy of an existing one. Moreover, recent evaluations have shown that, after low-intensity earthquakes, damage of non-structural parts strongly influences repair costs for typical multi-storey buildings. In this paper, an innovative concept for infill panels and partitions is presented, in which (either concrete or clay) blocks are connected, rather than with the usual mortar layers, by means of recycled-plastic joints. A comparison is also carried out with respect to conventional infill typologies, by evaluating their performance in terms of energy efficiency and acoustic. A brief description of seismic performances of innovative infill panels are shown at the end of work.

Seaweed biopolymers as additives for unfired clay bricks

Unfired clay bricks are an environmentally friendly alternative to conventional masonry materials such as fired bricks and concrete blocks but their use is currently limited by their relatively poor mechanical and durability properties. While products like cement and lime are commonly added to earthen materials in an effort to improve their physical performance, these additives can also have a negative influence on the overall environmental impact. The purpose of this research is to investigate the use of alginate, a natural and renewable biopolymer obtained from brown seaweeds, as an admixture for unfired clay blocks. A total of 5 different alginates have been investigated and combined with 3 soil compositions to create prototype specimens which have then been characterised and compared in relation to flexural and compressive strength, microstructure, abrasive strength and hygroscopic behaviour. The results demonstrate that improvements in mechanical strength are dependent on the type of alginate used and the composition of the soil. The greatest increase in compressive strength is achieved using an alginate sourced from the Laminaria Hyperborea seaweed and offers a value more than double that of the equivalent control specimen. Increases in the alginate dosage do not necessarily lead to an increase in strength suggesting that there is an optimum concentration at which strength improvement is most effective.

Analytical modelling of masonry-infilled steel frames

Masonry itself is a composite heterogeneous material whose structural behaviour is strongly affected by many influencing parameters with a wide range of possible values, construction procedures as well as care methods taken afterwards. When the masonry panel is added into the surrounding frame the complex interactive frame-infill system is established exhibiting highly nonlinear inelastic structural behaviour. Therefore, the analytical modelling of masonry-infilled frame structures is a very complex task that demands various data matching given in-situ conditions, otherwise applied methods and analytical models used have only a theoretical value. In this paper analytical modelling of infilled steel frame structures is based on previously experimentally calibrated data. The base for calibration of analytical models was experimental testing of one-bay, one-storey infilled steel frames conducted at the Faculty of Civil Engineering, Josip Juraj Strossmayer University of Osijek. Two series by three steel frames were infilled with perforated clay blocks (‘strong infill’) and autoclaved aerated concrete blocks (‘weak infill’) respectively. The significant difference in structural behaviour of these two kinds of masonry infill is observed and modelled. The macro-models (single-strut and three-strut model and infill-panel macro-model) and detailed 2D micro-models were applied. A total of eight analytical models were analysed with their relevant characteristics along with the quality of epresentation of the measured global and local results as well as their applicability.

Ensayos a mezclas de barro estabilizadas para el relleno y empañetado de paredes de Bahareque

The buildings of bahareque deteriorate mostly due to the vulnerability of the mud to moisture and the use of not adequate mixtures in its repairs. In order to improve the mud mixtures of the filling and mud cover of bahareque walls, was carried out a research whose results are presented in this article. This research studied the behavior of mud mixtures stabilized with cement and/or lime, to the effects of water. For this purpose a series of standardized tests were performed and it was designed a customized absorption test for the proposed stabilized mud mixtures. Mud mixtures with 10% of additives for the filling, and up to 15% of additives for the mud cover were proposed. In the mixtures was also added debris of clay or cement blocks to replace the stones that are usually used in the bahareque of the Zulia state, Venezuela. Due to the uniformity in the results of the mixtures with cement and lime additives, it is concluded that any of the proposed mixtures can be used in a rehabilitation of bahareque walls, but it is recommended the mud mixture with 10 percent of cement and clay blocks, because it had the lowest values of water absorption, that is to say, it is the most waterproof.

Suitability of Large Sized Compacted Baked Clay Blocks as a Walling Material

Some disadvantages associated with conventional brick masonry are: high cost of construction, lower compressive strength and less durability. In order to resolve these problems, a new technique of constructing walls using large size baked clay blocks is introduced. For this purpose, clay blocks of size 150 mm × 300 mm × 1980 mm were cast at a pressure of 6 MPa, and fired at a temperature of 700℃. In this paper, compressive strength and tensile strength of baked clay were investigated in order to find its suitability as a walling material for low cost houses. Cubes of 150 mm sides were tested in compression and the beams were tested in flexure. The results showed that compressive strength of baked clay cubes was found to be 10 MPa and tensile strength, in terms of modulus of rupture, was found to be 2.3 MPa. Since the baked clay blocks are larger in size than traditional bricks, it is inferred that the blocks could be used as a cheaper and stronger walling material.

Three-dimensional micromodel of clay block masonry wall

Three-dimensional micromodel of clay block masonry wall

Three-dimensional micromodel of clay block masonry wall

In designing and implementing earthquake resistance for clay block masonry infill integrated into a structural frame, with or without openings, the infill wall should be taken into account. Presumably, simplified models, acceptable for practical use, could be applied for that purpose. However, the anisotropy of clay block masonry units, masonry mortar joints, and unit contact properties as well as the high variance of material properties limit their ability to describe the actual earthquake resistance of clay block masonry. In this work, we consider a three-dimensional micromodel of a clay block masonry wall, with the inclusion of masonry unit anisotropy and masonry mortar joint and unit contact properties. To avoid the excessive calibration procedure of the wall micromodel, the wall constituents were calibrated separately beforehand, which resulted in a high correlation of computational and experimental results without further need for calibration. Using a calibrated micromodel, the influence of variance in material properties on the wall's resistance was investigated. The influence was showed not to be negligible, which may significantly affect the presumed behaviour of the whole structure.

Material model for modeling clay at high strain rates

Modeling clay is a soft malleable material made from oils and waxes. This material is fundamental for ballistic evaluation of body armors because it is used as backing material in ballistic tests. After a ballistic impact, a back-face indentation is measured to assess performance of the armor. Due to the important role of modeling clay in this particular application, its mechanical characterization and comprehension of penetration mechanics are essential for development of new personal protection systems. This paper presents a two-step computational methodology to calibrate parameters of a Cowper–Symonds material model for modeling clay at characteristic strain rates up to 1.8×104 s−1. In the first stage, a high-speed camera is used to record the penetration of a gas-gun launched cylindrical mass with a hemispherical cap into a block of clay. Image-processing software is used to capture the tail of the projectile as it penetrates into the clay. These data are then used to sample the penetration depth as function of time. In the second stage, an in-house developed model of penetration, based on both the spherical cavity expansion theory and the Tate penetration equation, is used to determine, by inverse analysis, the parameters of the Cowper–Symonds clay model. The proposed constitutive relationship for clay and the determined material parameters can be applied accurately to problems involving high strain rates.